On Wednesday, Jan 26th at 16:00 CET, we will continue with our virtual talk series for the NextAID project. The next presentation will be given by Dr. Carsten Volz (HIPS). To register, please contact Gerrit Großmann.

Title: Screening for antimicrobial compounds upon solid phase (co-)cultivation 

Abstract: Standard screening procedures for bioactive natural compounds routinely include cultivation in liquid culture followed by activity-guided fractionation of the crude extracts. In the past decades, interesting antimicrobial compounds could be isolated from Myxobacteria by such an approach. However, in the era of quick and cheap availability of sequenced genomes a striking discrepancy between the number of novel antimicrobials and the number of encoded secondary metabolite gene clusters in such genomes becomes apparent. It is tempting to speculate that these so called “silent gene clusters” will not be “switched on” and potential anti-infectives remain undiscovered unless appropriate culture conditions will be applied. In our screening approach, we try to induce production by using solid-phase cultivation of putative producer strains in the presence and absence of putative pathogenic target bacteria. Our experiments show that many strains, which have been considered not to produce an antibiotic based on previous conventional screening procedures, are indeed able to form unknown bioactive compounds that are being subjected to further characterization. The identification of the biosynthetic gene clusters encoding functions responsible for compound formation shall be achieved via a comparative transcriptomics approach.